Biomedical Engineering Reference
In-Depth Information
underlying the gesture of cutting a leg, such as making an S-shape, is
manipulated in a variety of contexts, that is, in real production time and
on a variety of ducks. This diversity of context becomes a source of reflec-
tion in the constitution of new modes of operation.
Although gestural variability is essential, it does not presume that
it is possible to develop the chosen gestures and modes of operation.
In the design of workstations, prescriptions, training systems, etc., it is
not enough to allow for and foresee gestural variability for operators to
develop new gestures. It is also important to open up reflective spaces,
spaces and times to develop gestures.
Opening up reflective spaces
for the development of gestures
Reflectivity plays an irreplaceable part in the development of gestures at
work. This is because gestures are inseparably productive and construc-
tive (Delgoulet and Vidal-Gomel, this volume; Rabardel and Samurçay,
2001). Obviously, the gesture makes it possible to perform a task and
achieve a productive goal (the productive dimension). Simultaneously,
however, it makes it possible to construct one's own experience (the con-
structive dimension). This makes it possible to understand how know-
how and experience allow operators to protect themselves. The issue that
arises for ergonomists is therefore: how can one design work environ-
ments that allow the construction of this experience and the development
of gestures? Reflectivity is the driving engine in this development, and the
goal is to include leeway in work systems, allowing operators to become
reflective practitioners (Schön, 1983), not simple underlings.
From a cognitive viewpoint, gestural expertise manifests itself through
the incorporated (Leplat, 1995) and largely implicit and tacit (Polanyi, 1969)
character of the knowledge underlying gestures. Most scientific works on
the subject agree that the development of expertise in gestural production
is accompanied by a less cognitive effort. For example, in Rasmussen's
(1983) Skills, Rules, Knowledge (SRK) model, the three levels of expertise
are characterized by a specific level of internalization/externalization.
Within this framework, the sensorimotor level of skills is the level that is
the most internalized and the one that can least easily be elicited.
In acknowledging this fact, several questions emerge: What are
the lessons that operators can draw from their own experience, if the
most internalized dimension of that experience is largely implicit and
incorporated - and therefore is the one that is least accessible to verbal-
ization? How can ergonomists act on situations to facilitate externaliza-
tion, as well as reflection on the incorporated and tacit dimensions of
gestural experience?
